ASTM D5611-94e1

e1
Designation: D 5611 – 94
Standard Guide for
Conducting a Sensitivity Analysis for a Ground-Water Flow
1
Model Application
This standard is issued under the fixed designation D 5611; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1
e NOTE—Paragraph 1.9 was added editorially October 1998.
1. Scope environmental modeling, such as Practice E 978.
1.7 The values stated in inch-pound units are to be regarded
1.1 This guide covers techniques that should be used to
as the standard. The SI units given in parentheses are for
conduct a sensitivity analysis for a ground-water flow model.
information only.
The sensitivity analysis results in quantitative relationships
1.8 This standard does not purport to address all of the
between model results and the input hydraulic properties or
safety concerns, if any, associated with its use. It is the
boundary conditions of the aquifers.
responsibility of the user of this standard to establish appro-
1.2 After a ground-water flow model has been calibrated, a
priate safety and health practices and determine the applica-
sensitivity analysis may be performed. Examination of the
bility of regulatory limitations prior to use.
sensitivity of calibration residuals and model conclusions to
1.9 This guide offers an organized collection of information
model inputs is a method for assessing the adequacy of the
or a series of options and does not recommend a specific
model with respect to its intended function.
course of action. This document cannot replace education or
1.3 After a model has been calibrated, a modeler may vary
experience and should be used in conjunction with professional
the value of some aspect of the conditions applying solely to
judgment. Not all aspects of this guide may be applicable in all
the prediction simulations in order to satisfy some design
circumstances. This ASTM standard is not intended to repre-
criteria. For example, the number and locations of proposed
sent or replace the standard of care by which the adequacy of
pumping wells may be varied in order to minimize the required
a given professional service must be judged, nor should this
discharge. Insofar as these aspects are controllable, variation of
document be applied without consideration of a project’s many
these parameters is part of an optimization procedure, and, for
unique aspects. The word “Standard” in the title of this
the purposes of this guide, would not be considered to be a
document means only that the document has been approved
sensitivity analysis. On the other hand, estimates of future
through the ASTM consensus process.
conditions that are not controllable, such as the recharge during
a postulated drought of unknown duration and severity, would
2. Referenced Documents
be considered as candidates for a sensitivity analysis.
2.1 ASTM Standards:
1.4 This guide presents the simplest acceptable techniques
D 653 Terminology Relating to Soil, Rock, and Contained
for conducting a sensitivity analysis. Other techniques have
2
Fluids
been developed by researchers and could be used in lieu of the
D 5447 Guide for Application of a Ground-Water Flow
techniques in this guide.
3
Model to a Site-Specific Problem
1.5 This guide is written for performing sensitivity analyses
D 5490 Guide for Comparing Ground-Water Flow Model
for ground-water flow models. However, these techniques
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Simulations to Site-Specific Information
could be applied to other types of ground-water related models,
E 978 Practice for Evaluating Environmental Fate Models
such as analytical models, multi-phase flow models, non-
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of Chemicals
continuum (karst or fracture flow) models, or mass transport
models.
3. Terminology
1.6 This guide is one of a series on ground-water modeling
3.1 Definitions:
codes (software) and their applications, such as Guide D 5447
3.1.1 boundary condition—a mathematical expression of a
and Guide D 5490. Other standards have been prepared on
1
This guide is under the jurisdiction of ASTM Committee D-18 on Soil and
2
Rockand is the direct responsibility of Subcommittee D18.21 on Ground Water and Annual Book of ASTM Standards, Vol 04.08.
3
Vadose Investigations. Annual Book of ASTM Standards, Vol 04.09.
4
Current edition approved Sept. 15, 1994. Published October 1994. Annual Book of ASTM Standards, Vol 11.04.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
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D 5611
state of the physical system that constrains the equations of the conclusions about a physical hydrogeologic system (for ex-
mathematical model. ample, estimating the capture zone of a proposed extraction
3.1.2 calibration—the process of refining the model repre- well), a sensitivity analysis can be perfor
...